diff --git a/components/style/properties/helpers.mako.rs b/components/style/properties/helpers.mako.rs
index 29b7e9e3f8b..22046774fe5 100644
--- a/components/style/properties/helpers.mako.rs
+++ b/components/style/properties/helpers.mako.rs
@@ -13,8 +13,11 @@
     <%def name="predefined_type_inner(name, type, initial_value, parse_method)">
         #[allow(unused_imports)]
         use app_units::Au;
+        #[allow(unused_imports)]
         use cssparser::{Color as CSSParserColor, RGBA};
+        #[allow(unused_imports)]
         use values::specified::AllowQuirks;
+        #[allow(unused_imports)]
         use smallvec::SmallVec;
         pub use values::specified::${type} as SpecifiedValue;
         pub mod computed_value {
@@ -78,15 +81,22 @@
         % if not gecko_only:
             use smallvec::SmallVec;
             use std::fmt;
+            #[allow(unused_imports)]
             use values::HasViewportPercentage;
             use style_traits::ToCss;
 
             pub mod single_value {
+                #[allow(unused_imports)]
                 use cssparser::Parser;
+                #[allow(unused_imports)]
                 use parser::{Parse, ParserContext};
+                #[allow(unused_imports)]
                 use properties::ShorthandId;
+                #[allow(unused_imports)]
                 use values::computed::{Context, ToComputedValue};
+                #[allow(unused_imports)]
                 use values::{computed, specified};
+                #[allow(unused_imports)]
                 use values::{Auto, Either, None_, Normal};
                 ${caller.body()}
             }
@@ -198,6 +208,7 @@
             }
 
             pub fn parse(context: &ParserContext, input: &mut Parser) -> Result<SpecifiedValue, ()> {
+                #[allow(unused_imports)]
                 use parser::parse_space_or_comma_separated;
 
                 <%
@@ -253,22 +264,35 @@
     %>
     /// ${property.spec}
     pub mod ${property.ident} {
-        #![allow(unused_imports)]
         % if not property.derived_from:
+            #[allow(unused_imports)]
             use cssparser::Parser;
+            #[allow(unused_imports)]
             use parser::{Parse, ParserContext};
+            #[allow(unused_imports)]
             use properties::{UnparsedValue, ShorthandId};
         % endif
+        #[allow(unused_imports)]
         use values::{Auto, Either, None_, Normal};
+        #[allow(unused_imports)]
         use cascade_info::CascadeInfo;
+        #[allow(unused_imports)]
         use error_reporting::ParseErrorReporter;
+        #[allow(unused_imports)]
         use properties::longhands;
+        #[allow(unused_imports)]
         use properties::{DeclaredValue, LonghandId, LonghandIdSet};
+        #[allow(unused_imports)]
         use properties::{CSSWideKeyword, ComputedValues, PropertyDeclaration};
+        #[allow(unused_imports)]
         use properties::style_structs;
+        #[allow(unused_imports)]
         use stylearc::Arc;
+        #[allow(unused_imports)]
         use values::computed::{Context, ToComputedValue};
+        #[allow(unused_imports)]
         use values::{computed, generics, specified};
+        #[allow(unused_imports)]
         use Atom;
         ${caller.body()}
         #[allow(unused_variables)]
@@ -454,7 +478,6 @@
         keyword = keyword=Keyword(name, values, **keyword_kwargs)
     %>
     <%call expr="longhand(name, keyword=Keyword(name, values, **keyword_kwargs), **kwargs)">
-        use values::HasViewportPercentage;
         use properties::longhands::system_font::SystemFont;
         use std::fmt;
         use style_traits::ToCss;
@@ -576,7 +599,6 @@
             impl ComputedValueAsSpecified for SpecifiedValue {}
         % endif
 
-        use values::HasViewportPercentage;
         no_viewport_percentage!(SpecifiedValue);
     </%call>
 </%def>
@@ -738,7 +760,6 @@
     % if shorthand:
     /// ${shorthand.spec}
     pub mod ${shorthand.ident} {
-        #[allow(unused_imports)]
         use cssparser::Parser;
         use parser::ParserContext;
         use properties::{PropertyDeclaration, ParsedDeclaration};
diff --git a/components/style/properties/longhand/background.mako.rs b/components/style/properties/longhand/background.mako.rs
index 7e2fd6b2196..699395dd9f2 100644
--- a/components/style/properties/longhand/background.mako.rs
+++ b/components/style/properties/longhand/background.mako.rs
@@ -34,7 +34,6 @@ ${helpers.predefined_type("background-image", "ImageLayer",
                           spec="https://drafts.csswg.org/css-backgrounds/#the-background-repeat">
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
 
     define_css_keyword_enum!(RepeatKeyword:
                              "repeat" => Repeat,
@@ -163,11 +162,8 @@ ${helpers.single_keyword("background-origin",
 
 <%helpers:vector_longhand name="background-size" animation_value_type="ComputedValue" extra_prefixes="webkit"
                           spec="https://drafts.csswg.org/css-backgrounds/#the-background-size">
-    use cssparser::Token;
-    use std::ascii::AsciiExt;
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
 
     #[allow(missing_docs)]
     pub mod computed_value {
diff --git a/components/style/properties/longhand/border.mako.rs b/components/style/properties/longhand/border.mako.rs
index 8b1adaf02bc..8c775b682c0 100644
--- a/components/style/properties/longhand/border.mako.rs
+++ b/components/style/properties/longhand/border.mako.rs
@@ -62,7 +62,6 @@ ${helpers.gecko_keyword_conversion(Keyword('border-style',
                        products="gecko">
         use std::fmt;
         use style_traits::ToCss;
-        use values::HasViewportPercentage;
         use values::specified::CSSColor;
         no_viewport_percentage!(SpecifiedValue);
 
@@ -205,7 +204,6 @@ ${helpers.predefined_type("border-image-source", "ImageLayer",
                    spec="https://drafts.csswg.org/css-backgrounds/#border-image-outset">
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
     use values::specified::{LengthOrNumber, Number};
 
     pub mod computed_value {
@@ -310,13 +308,11 @@ ${helpers.predefined_type("border-image-source", "ImageLayer",
                    spec="https://drafts.csswg.org/css-backgrounds/#border-image-repeat">
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
 
     no_viewport_percentage!(SpecifiedValue);
 
     pub mod computed_value {
         pub use super::RepeatKeyword;
-        use values::computed;
 
         #[derive(Debug, Clone, PartialEq)]
         #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
@@ -388,7 +384,6 @@ ${helpers.predefined_type("border-image-source", "ImageLayer",
                    spec="https://drafts.csswg.org/css-backgrounds/#border-image-width">
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
     use values::specified::{LengthOrPercentage, Number};
 
     pub mod computed_value {
@@ -574,7 +569,6 @@ ${helpers.predefined_type("border-image-source", "ImageLayer",
                    spec="https://drafts.csswg.org/css-backgrounds/#border-image-slice">
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
     use values::computed::NumberOrPercentage as ComputedNumberOrPercentage;
     use values::specified::{NumberOrPercentage, Percentage};
 
diff --git a/components/style/properties/longhand/box.mako.rs b/components/style/properties/longhand/box.mako.rs
index cc5733523db..fe9aa583a2b 100644
--- a/components/style/properties/longhand/box.mako.rs
+++ b/components/style/properties/longhand/box.mako.rs
@@ -31,7 +31,6 @@
     %>
     use values::computed::ComputedValueAsSpecified;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
     no_viewport_percentage!(SpecifiedValue);
 
     pub mod computed_value {
@@ -170,7 +169,6 @@ ${helpers.single_keyword("position", "static absolute relative fixed",
                                   gecko_inexhaustive="True"
                                   gecko_ffi_name="mFloat"
                                   spec="https://drafts.csswg.org/css-box/#propdef-float">
-    use values::HasViewportPercentage;
     no_viewport_percentage!(SpecifiedValue);
     impl ToComputedValue for SpecifiedValue {
         type ComputedValue = computed_value::T;
@@ -209,7 +207,6 @@ ${helpers.single_keyword("position", "static absolute relative fixed",
                                   gecko_enum_prefix="StyleClear"
                                   gecko_ffi_name="mBreakType"
                                   spec="https://www.w3.org/TR/CSS2/visuren.html#flow-control">
-    use values::HasViewportPercentage;
     no_viewport_percentage!(SpecifiedValue);
     impl ToComputedValue for SpecifiedValue {
         type ComputedValue = computed_value::T;
@@ -263,7 +260,6 @@ ${helpers.single_keyword("position", "static absolute relative fixed",
                    spec="https://www.w3.org/TR/CSS2/visudet.html#propdef-vertical-align">
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
     use values::specified::AllowQuirks;
 
     <% vertical_align = data.longhands_by_name["vertical-align"] %>
@@ -312,10 +308,9 @@ ${helpers.single_keyword("position", "static absolute relative fixed",
 
     /// The computed value for `vertical-align`.
     pub mod computed_value {
-        use app_units::Au;
         use std::fmt;
         use style_traits::ToCss;
-        use values::{CSSFloat, computed};
+        use values::computed;
 
         /// The keywords are the same, and the `LengthOrPercentage` is computed
         /// here.
@@ -417,7 +412,6 @@ ${helpers.single_keyword("overflow-x", "visible hidden scroll auto",
     use values::specified::Time;
 
     pub use values::specified::Time as SpecifiedValue;
-    use values::HasViewportPercentage;
     no_viewport_percentage!(SpecifiedValue);
 
     pub mod computed_value {
@@ -449,7 +443,6 @@ ${helpers.single_keyword("overflow-x", "visible hidden scroll auto",
     use values::specified::Number;
     use euclid::point::{Point2D, TypedPoint2D};
     use std::fmt;
-    use std::marker::PhantomData;
     use style_traits::ToCss;
 
     // FIXME: This could use static variables and const functions when they are available.
@@ -490,7 +483,6 @@ ${helpers.single_keyword("overflow-x", "visible hidden scroll auto",
 
     pub mod computed_value {
         use euclid::point::Point2D;
-        use parser::{Parse, ParserContext};
         use std::fmt;
         use style_traits::ToCss;
         use super::FunctionKeyword;
@@ -755,7 +747,6 @@ ${helpers.single_keyword("overflow-x", "visible hidden scroll auto",
         }
     }
 
-    use values::HasViewportPercentage;
     no_viewport_percentage!(SpecifiedValue);
 
     #[inline]
@@ -786,8 +777,6 @@ ${helpers.single_keyword("overflow-x", "visible hidden scroll auto",
     pub use properties::animated_properties::TransitionProperty as SpecifiedValue;
 
     pub mod computed_value {
-        use std::fmt;
-        use style_traits::ToCss;
         // NB: Can't generate the type here because it needs all the longhands
         // generated beforehand.
         pub use super::SpecifiedValue as T;
@@ -801,7 +790,6 @@ ${helpers.single_keyword("overflow-x", "visible hidden scroll auto",
         TransitionProperty::All
     }
 
-    use values::HasViewportPercentage;
     no_viewport_percentage!(SpecifiedValue);
 
     impl ComputedValueAsSpecified for SpecifiedValue { }
@@ -830,10 +818,9 @@ ${helpers.single_keyword("overflow-x", "visible hidden scroll auto",
                           spec="https://drafts.csswg.org/css-animations/#propdef-animation-name">
     use Atom;
     use std::fmt;
-    use std::ops::Deref;
     use style_traits::ToCss;
     use values::computed::ComputedValueAsSpecified;
-    use values::{HasViewportPercentage, KeyframesName};
+    use values::KeyframesName;
 
     pub mod computed_value {
         pub use super::SpecifiedValue as T;
@@ -928,7 +915,6 @@ ${helpers.single_keyword("overflow-x", "visible hidden scroll auto",
     use std::fmt;
     use style_traits::ToCss;
     use values::computed::ComputedValueAsSpecified;
-    use values::HasViewportPercentage;
 
     pub mod computed_value {
         pub use super::SpecifiedValue as T;
@@ -1036,7 +1022,6 @@ ${helpers.single_keyword("animation-fill-mode",
                    spec="Nonstandard (https://www.w3.org/TR/2015/WD-css-snappoints-1-20150326/#scroll-snap-points)">
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
     use values::specified::LengthOrPercentage;
 
     pub mod computed_value {
@@ -1157,9 +1142,8 @@ ${helpers.predefined_type("scroll-snap-coordinate",
     use values::specified::{LengthOrNumber, LengthOrPercentageOrNumber as LoPoNumber, Number};
     use style_traits::ToCss;
     use style_traits::values::Css;
-    use values::HasViewportPercentage;
 
-    use std::fmt::{self, Display};
+    use std::fmt;
 
     pub mod computed_value {
         use app_units::Au;
@@ -2121,7 +2105,6 @@ ${helpers.single_keyword("transform-style",
     use app_units::Au;
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
     use values::specified::{NoCalcLength, LengthOrPercentage, Percentage};
 
     pub mod computed_value {
@@ -2239,7 +2222,6 @@ ${helpers.single_keyword("transform-style",
                    spec="https://drafts.csswg.org/css-contain/#contain-property">
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
     use values::computed::ComputedValueAsSpecified;
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
@@ -2392,7 +2374,6 @@ ${helpers.single_keyword("-moz-orient",
     use cssparser::serialize_identifier;
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
     use values::computed::ComputedValueAsSpecified;
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
@@ -2465,7 +2446,6 @@ ${helpers.predefined_type("shape-outside", "basic_shape::ShapeWithShapeBox",
     use gecko_bindings::structs;
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
     use values::computed::ComputedValueAsSpecified;
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
diff --git a/components/style/properties/longhand/color.mako.rs b/components/style/properties/longhand/color.mako.rs
index e4c3ef4b1fb..20faeec8485 100644
--- a/components/style/properties/longhand/color.mako.rs
+++ b/components/style/properties/longhand/color.mako.rs
@@ -14,7 +14,7 @@
     use cssparser::RGBA;
     use std::fmt;
     use style_traits::ToCss;
-    use values::specified::{AllowQuirks, Color, CSSColor, CSSRGBA};
+    use values::specified::{AllowQuirks, Color, CSSColor};
 
     impl ToComputedValue for SpecifiedValue {
         type ComputedValue = computed_value::T;
@@ -122,6 +122,7 @@
 
         impl SystemColor {
             pub fn parse(input: &mut Parser) -> Result<Self, ()> {
+                #[cfg(feature = "gecko")]
                 use std::ascii::AsciiExt;
                 static PARSE_ARRAY: &'static [(&'static str, SystemColor); ${len(system_colors)}] = &[
                     % for color in system_colors:
diff --git a/components/style/properties/longhand/counters.mako.rs b/components/style/properties/longhand/counters.mako.rs
index 4c4ac955d5b..c961e073b21 100644
--- a/components/style/properties/longhand/counters.mako.rs
+++ b/components/style/properties/longhand/counters.mako.rs
@@ -9,12 +9,11 @@
 <%helpers:longhand name="content" boxed="True" animation_value_type="none"
                    spec="https://drafts.csswg.org/css-content/#propdef-content">
     use cssparser::Token;
-    use std::ascii::AsciiExt;
     use values::computed::ComputedValueAsSpecified;
     #[cfg(feature = "gecko")]
     use values::generics::CounterStyleOrNone;
+    #[cfg(feature = "gecko")]
     use values::specified::url::SpecifiedUrl;
-    use values::HasViewportPercentage;
 
     #[cfg(feature = "servo")]
     use super::list_style_type;
@@ -29,6 +28,7 @@
         use cssparser;
         use std::fmt;
         use style_traits::ToCss;
+        #[cfg(feature = "gecko")]
         use values::specified::url::SpecifiedUrl;
 
         #[cfg(feature = "servo")]
@@ -256,11 +256,9 @@
                    spec="https://drafts.csswg.org/css-lists/#propdef-counter-increment">
     use std::fmt;
     use style_traits::ToCss;
-    use super::content;
-    use values::{HasViewportPercentage, CustomIdent};
+    use values::CustomIdent;
 
-    use cssparser::{Token, serialize_identifier};
-    use std::borrow::{Cow, ToOwned};
+    use cssparser::Token;
 
     #[derive(Debug, Clone, PartialEq)]
     pub struct SpecifiedValue(pub Vec<(CustomIdent, specified::Integer)>);
@@ -278,7 +276,6 @@
             fn to_css<W>(&self, dest: &mut W) -> fmt::Result
                 where W: fmt::Write,
             {
-                use cssparser::serialize_identifier;
                 if self.0.is_empty() {
                     return dest.write_str("none")
                 }
@@ -348,8 +345,6 @@
     }
 
     pub fn parse_common(context: &ParserContext, default_value: i32, input: &mut Parser) -> Result<SpecifiedValue, ()> {
-        use std::ascii::AsciiExt;
-
         if input.try(|input| input.expect_ident_matching("none")).is_ok() {
             return Ok(SpecifiedValue(Vec::new()))
         }
diff --git a/components/style/properties/longhand/effects.mako.rs b/components/style/properties/longhand/effects.mako.rs
index c10e1b8f018..730142b76a7 100644
--- a/components/style/properties/longhand/effects.mako.rs
+++ b/components/style/properties/longhand/effects.mako.rs
@@ -18,10 +18,8 @@ ${helpers.predefined_type("opacity",
                           animation_value_type="IntermediateBoxShadowList"
                           extra_prefixes="webkit"
                           spec="https://drafts.csswg.org/css-backgrounds/#box-shadow">
-    use cssparser;
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
 
     pub type SpecifiedValue = specified::Shadow;
 
@@ -47,9 +45,6 @@ ${helpers.predefined_type("opacity",
     }
 
     pub mod computed_value {
-        use app_units::Au;
-        use std::fmt;
-        use values::computed;
         use values::computed::Shadow;
 
         pub type T = Shadow;
@@ -91,11 +86,13 @@ ${helpers.predefined_type("clip",
                    flags="CREATES_STACKING_CONTEXT FIXPOS_CB"
                    spec="https://drafts.fxtf.org/filters/#propdef-filter">
     //pub use self::computed_value::T as SpecifiedValue;
-    use cssparser;
     use std::fmt;
-    use style_traits::{self, ToCss};
+    use style_traits::ToCss;
     use values::{CSSFloat, HasViewportPercentage};
-    use values::specified::{Angle, CSSColor, Length, Shadow};
+    use values::specified::{Angle, Length};
+    #[cfg(feature = "gecko")]
+    use values::specified::Shadow;
+    #[cfg(feature = "gecko")]
     use values::specified::url::SpecifiedUrl;
 
     #[derive(Clone, Debug, HasViewportPercentage, PartialEq)]
@@ -133,8 +130,10 @@ ${helpers.predefined_type("clip",
     pub mod computed_value {
         use app_units::Au;
         use values::CSSFloat;
-        use values::computed::{CSSColor, Shadow};
+        #[cfg(feature = "gecko")]
+        use values::computed::Shadow;
         use values::computed::Angle;
+        #[cfg(feature = "gecko")]
         use values::specified::url::SpecifiedUrl;
 
         #[derive(Clone, PartialEq, Debug)]
diff --git a/components/style/properties/longhand/font.mako.rs b/components/style/properties/longhand/font.mako.rs
index 2ed4e170cc4..09149a301e9 100644
--- a/components/style/properties/longhand/font.mako.rs
+++ b/components/style/properties/longhand/font.mako.rs
@@ -68,14 +68,11 @@
     use self::computed_value::{FontFamily, FamilyName};
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
-    use values::computed::ComputedValueAsSpecified;
 
     no_viewport_percentage!(SpecifiedValue);
 
     pub mod computed_value {
         use cssparser::{CssStringWriter, Parser, serialize_identifier};
-        use properties::longhands::system_font::SystemFont;
         use std::fmt::{self, Write};
         use Atom;
         use style_traits::ToCss;
@@ -355,7 +352,6 @@ ${helpers.single_keyword_system("font-variant-caps",
                    spec="https://drafts.csswg.org/css-fonts/#propdef-font-weight">
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
     use properties::longhands::system_font::SystemFont;
 
     no_viewport_percentage!(SpecifiedValue);
@@ -449,7 +445,6 @@ ${helpers.single_keyword_system("font-variant-caps",
     }
 
     pub mod computed_value {
-        use std::fmt;
         #[derive(PartialEq, Eq, Copy, Clone, Hash, Debug)]
         #[cfg_attr(feature = "servo", derive(HeapSizeOf, Deserialize, Serialize))]
         #[repr(u16)]
@@ -557,7 +552,7 @@ ${helpers.single_keyword_system("font-variant-caps",
     use std::fmt;
     use style_traits::ToCss;
     use values::{FONT_MEDIUM_PX, HasViewportPercentage};
-    use values::specified::{AllowQuirks, FontRelativeLength, LengthOrPercentage, Length};
+    use values::specified::{AllowQuirks, FontRelativeLength, LengthOrPercentage};
     use values::specified::{NoCalcLength, Percentage};
     use values::specified::length::FontBaseSize;
 
@@ -694,8 +689,7 @@ ${helpers.single_keyword_system("font-variant-caps",
             type ComputedValue = Au;
             #[inline]
             fn to_computed_value(&self, cx: &Context) -> computed_value::T {
-                use gecko_bindings::bindings::Gecko_GetBaseSize;
-                use gecko_bindings::structs::{self, nsIAtom};
+                use gecko_bindings::structs::nsIAtom;
                 use values::specified::length::au_to_int_px;
                 // Data from nsRuleNode.cpp in Gecko
                 // Mapping from base size and HTML size to pixels
@@ -977,7 +971,6 @@ ${helpers.single_keyword_system("font-variant-caps",
     use properties::longhands::system_font::SystemFont;
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
 
     no_viewport_percentage!(SpecifiedValue);
 
@@ -1119,7 +1112,6 @@ ${helpers.single_keyword_system("font-variant-caps",
                    spec="https://drafts.csswg.org/css-fonts/#propdef-font-synthesis">
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
     use values::computed::ComputedValueAsSpecified;
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
@@ -1204,7 +1196,6 @@ ${helpers.single_keyword_system("font-kerning",
     use properties::longhands::system_font::SystemFont;
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
 
     no_viewport_percentage!(SpecifiedValue);
 
@@ -1340,7 +1331,6 @@ macro_rules! exclusive_value {
     use properties::longhands::system_font::SystemFont;
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
 
     no_viewport_percentage!(SpecifiedValue);
 
@@ -1481,7 +1471,6 @@ macro_rules! exclusive_value {
     use properties::longhands::system_font::SystemFont;
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
 
     no_viewport_percentage!(SpecifiedValue);
 
@@ -1632,7 +1621,6 @@ macro_rules! exclusive_value {
     use properties::longhands::system_font::SystemFont;
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
 
     no_viewport_percentage!(SpecifiedValue);
 
@@ -1785,8 +1773,6 @@ ${helpers.single_keyword_system("font-variant-position",
     use properties::longhands::system_font::SystemFont;
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
-    use values::computed::ComputedValueAsSpecified;
 
     #[derive(Debug, Clone, PartialEq)]
     pub enum SpecifiedValue {
@@ -1869,8 +1855,6 @@ ${helpers.single_keyword_system("font-variant-position",
             /// <string> [ on | off | <integer> ]
             fn parse(_context: &ParserContext, input: &mut Parser) -> Result<Self, ()> {
                 use std::io::Cursor;
-                use std::str;
-                use std::ops::Deref;
                 use byteorder::{ReadBytesExt, BigEndian};
 
                 let tag = try!(input.expect_string());
@@ -1929,7 +1913,6 @@ ${helpers.single_keyword_system("font-variant-position",
     use std::fmt;
     use style_traits::ToCss;
     use byteorder::{BigEndian, ByteOrder};
-    use values::HasViewportPercentage;
     no_viewport_percentage!(SpecifiedValue);
 
     #[derive(Debug, Clone, PartialEq, Eq)]
@@ -2064,7 +2047,6 @@ ${helpers.single_keyword_system("font-variant-position",
 
 <%helpers:longhand name="-x-lang" products="gecko" animation_value_type="none" internal="True"
                    spec="Internal (not web-exposed)">
-    use values::HasViewportPercentage;
     use values::computed::ComputedValueAsSpecified;
     pub use self::computed_value::T as SpecifiedValue;
 
@@ -2103,7 +2085,6 @@ ${helpers.single_keyword_system("font-variant-position",
                    predefined_type="Number" gecko_ffi_name="mScriptSizeMultiplier"
                    spec="Internal (not web-exposed)"
                    internal="True" disable_when_testing="True">
-    use values::HasViewportPercentage;
     use values::computed::ComputedValueAsSpecified;
     pub use self::computed_value::T as SpecifiedValue;
 
@@ -2130,7 +2111,6 @@ ${helpers.single_keyword_system("font-variant-position",
                    internal="True" disable_when_testing="True" need_clone="True">
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
 
     no_viewport_percentage!(SpecifiedValue);
 
@@ -2230,8 +2210,6 @@ ${helpers.single_keyword("-moz-math-variant",
     use gecko_bindings::structs::NS_MATHML_DEFAULT_SCRIPT_MIN_SIZE_PT;
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
-    use values::computed::ComputedValueAsSpecified;
     use values::specified::length::{AU_PER_PT, FontBaseSize, NoCalcLength};
 
     #[derive(Clone, Debug, HasViewportPercentage, PartialEq)]
diff --git a/components/style/properties/longhand/inherited_box.mako.rs b/components/style/properties/longhand/inherited_box.mako.rs
index 7c7cd67e8e9..c482e03dd62 100644
--- a/components/style/properties/longhand/inherited_box.mako.rs
+++ b/components/style/properties/longhand/inherited_box.mako.rs
@@ -68,7 +68,6 @@ ${helpers.single_keyword("image-rendering",
     use style_traits::ToCss;
     use values::specified::Angle;
 
-    use values::HasViewportPercentage;
     no_viewport_percentage!(SpecifiedValue);
 
     use std::f32::consts::PI;
@@ -207,7 +206,6 @@ ${helpers.single_keyword("image-rendering",
     use std::fmt;
     use style_traits::ToCss;
     use values::computed::ComputedValueAsSpecified;
-    use values::HasViewportPercentage;
 
     no_viewport_percentage!(SpecifiedValue);
 
diff --git a/components/style/properties/longhand/inherited_svg.mako.rs b/components/style/properties/longhand/inherited_svg.mako.rs
index d7acf552e89..1f06f0ca172 100644
--- a/components/style/properties/longhand/inherited_svg.mako.rs
+++ b/components/style/properties/longhand/inherited_svg.mako.rs
@@ -144,7 +144,6 @@ ${helpers.predefined_type("marker-end", "UrlOrNone", "Either::Second(None_)",
     use values::computed::ComputedValueAsSpecified;
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
 
     pub const NORMAL: u8 = 0;
     pub const FILL: u8 = 1;
diff --git a/components/style/properties/longhand/inherited_table.mako.rs b/components/style/properties/longhand/inherited_table.mako.rs
index e83d5143904..61229c3228f 100644
--- a/components/style/properties/longhand/inherited_table.mako.rs
+++ b/components/style/properties/longhand/inherited_table.mako.rs
@@ -25,7 +25,6 @@ ${helpers.single_keyword("caption-side", "top bottom",
     use app_units::Au;
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
     use values::specified::{AllowQuirks, Length};
 
     pub mod computed_value {
diff --git a/components/style/properties/longhand/inherited_text.mako.rs b/components/style/properties/longhand/inherited_text.mako.rs
index e967bb0eba1..83b0cf26179 100644
--- a/components/style/properties/longhand/inherited_text.mako.rs
+++ b/components/style/properties/longhand/inherited_text.mako.rs
@@ -10,7 +10,6 @@
                    spec="https://drafts.csswg.org/css2/visudet.html#propdef-line-height">
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
 
     #[derive(Clone, Debug, HasViewportPercentage, PartialEq)]
     #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
@@ -66,7 +65,6 @@
     }
     pub mod computed_value {
         use app_units::Au;
-        use std::fmt;
         use values::CSSFloat;
         #[derive(PartialEq, Copy, Clone, Debug)]
         #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
@@ -203,7 +201,6 @@ ${helpers.single_keyword("word-break",
                                   gecko_enum_prefix="StyleTextJustify"
                                   animation_value_type="none"
                                   spec="https://drafts.csswg.org/css-text/#propdef-text-justify">
-    use values::HasViewportPercentage;
     no_viewport_percentage!(SpecifiedValue);
 
     impl ToComputedValue for SpecifiedValue {
@@ -247,8 +244,6 @@ ${helpers.single_keyword("text-align-last",
 // TODO make this a shorthand and implement text-align-last/text-align-all
 <%helpers:longhand name="text-align" animation_value_type="none" need_clone="True"
                    spec="https://drafts.csswg.org/css-text/#propdef-text-align">
-    use values::computed::ComputedValueAsSpecified;
-    use values::HasViewportPercentage;
     no_viewport_percentage!(SpecifiedValue);
     pub mod computed_value {
         use style_traits::ToCss;
@@ -391,6 +386,7 @@ ${helpers.single_keyword("text-align-last",
             }
         }
     % else:
+        use values::computed::ComputedValueAsSpecified;
         impl ComputedValueAsSpecified for SpecifiedValue {}
         pub use self::computed_value::T as SpecifiedValue;
         pub fn parse(_context: &ParserContext, input: &mut Parser) -> Result<SpecifiedValue, ()> {
@@ -403,7 +399,6 @@ ${helpers.single_keyword("text-align-last",
                    spec="https://drafts.csswg.org/css-text/#propdef-letter-spacing">
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
     use values::specified::AllowQuirks;
 
     #[derive(Clone, Debug, HasViewportPercentage, PartialEq)]
@@ -480,7 +475,6 @@ ${helpers.single_keyword("text-align-last",
                    spec="https://drafts.csswg.org/css-text/#propdef-word-spacing">
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
     use values::specified::AllowQuirks;
 
     #[derive(Clone, Debug, HasViewportPercentage, PartialEq)]
@@ -561,7 +555,6 @@ ${helpers.single_keyword("text-align-last",
     use cssparser::RGBA;
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
     use values::computed::ComputedValueAsSpecified;
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
@@ -647,7 +640,6 @@ ${helpers.single_keyword("text-align-last",
                                   animation_value_type="none"
                                   spec="https://drafts.csswg.org/css-text/#propdef-white-space">
     use values::computed::ComputedValueAsSpecified;
-    use values::HasViewportPercentage;
     impl ComputedValueAsSpecified for SpecifiedValue {}
     no_viewport_percentage!(SpecifiedValue);
 
@@ -693,7 +685,6 @@ ${helpers.single_keyword("text-align-last",
     use std::fmt;
     use style_traits::ToCss;
     use values::specified::Shadow;
-    use values::HasViewportPercentage;
 
     #[derive(Clone, Debug, HasViewportPercentage, PartialEq)]
     #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
@@ -849,7 +840,6 @@ ${helpers.single_keyword("text-align-last",
     use std::fmt;
     use style_traits::ToCss;
     use unicode_segmentation::UnicodeSegmentation;
-    use values::HasViewportPercentage;
 
     no_viewport_percentage!(SpecifiedValue);
 
@@ -1055,7 +1045,6 @@ ${helpers.single_keyword("text-align-last",
                    spec="https://drafts.csswg.org/css-text-decor/#propdef-text-emphasis-position">
     use std::fmt;
     use values::computed::ComputedValueAsSpecified;
-    use values::HasViewportPercentage;
     use style_traits::ToCss;
 
     define_css_keyword_enum!(HorizontalWritingModeValue:
diff --git a/components/style/properties/longhand/list.mako.rs b/components/style/properties/longhand/list.mako.rs
index 14084f894d2..90d9a9e3f67 100644
--- a/components/style/properties/longhand/list.mako.rs
+++ b/components/style/properties/longhand/list.mako.rs
@@ -36,7 +36,6 @@ ${helpers.single_keyword("list-style-position", "outside inside", animation_valu
         use std::fmt;
         use style_traits::ToCss;
         use values::CustomIdent;
-        use values::HasViewportPercentage;
         use values::computed::ComputedValueAsSpecified;
         use values::generics::CounterStyleOrNone;
 
@@ -105,7 +104,6 @@ ${helpers.single_keyword("list-style-position", "outside inside", animation_valu
                    boxed="${product == 'gecko'}"
                    spec="https://drafts.csswg.org/css-lists/#propdef-list-style-image">
     use std::fmt;
-    use values::HasViewportPercentage;
     use values::computed::ComputedValueAsSpecified;
     use values::specified::UrlOrNone;
     pub use self::computed_value::T as SpecifiedValue;
@@ -158,7 +156,6 @@ ${helpers.single_keyword("list-style-position", "outside inside", animation_valu
     use std::fmt;
     use style_traits::ToCss;
     use values::computed::ComputedValueAsSpecified;
-    use values::HasViewportPercentage;
 
     pub use self::computed_value::T as SpecifiedValue;
 
diff --git a/components/style/properties/longhand/outline.mako.rs b/components/style/properties/longhand/outline.mako.rs
index 88d34f964d5..3d0a22f08d4 100644
--- a/components/style/properties/longhand/outline.mako.rs
+++ b/components/style/properties/longhand/outline.mako.rs
@@ -17,11 +17,7 @@ ${helpers.predefined_type("outline-color", "CSSColor", "computed::CSSColor::Curr
 
 <%helpers:longhand name="outline-style" need_clone="True" animation_value_type="none"
                    spec="https://drafts.csswg.org/css-ui/#propdef-outline-style">
-
-    use std::fmt;
-    use style_traits::ToCss;
     use values::specified::BorderStyle;
-    use values::computed::ComputedValueAsSpecified;
 
     pub type SpecifiedValue = Either<Auto, BorderStyle>;
 
@@ -66,10 +62,8 @@ ${helpers.predefined_type("outline-color", "CSSColor", "computed::CSSColor::Curr
 
 <%helpers:longhand name="outline-width" animation_value_type="ComputedValue"
                    spec="https://drafts.csswg.org/css-ui/#propdef-outline-width">
-    use app_units::Au;
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
 
     impl ToCss for SpecifiedValue {
         fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
diff --git a/components/style/properties/longhand/pointing.mako.rs b/components/style/properties/longhand/pointing.mako.rs
index 77edc71e000..e04a2fc09b6 100644
--- a/components/style/properties/longhand/pointing.mako.rs
+++ b/components/style/properties/longhand/pointing.mako.rs
@@ -9,8 +9,8 @@
 <%helpers:longhand name="cursor" boxed="${product == 'gecko'}" animation_value_type="none"
   spec="https://drafts.csswg.org/css-ui/#cursor">
     pub use self::computed_value::T as SpecifiedValue;
-    use values::HasViewportPercentage;
     use values::computed::ComputedValueAsSpecified;
+    #[cfg(feature = "gecko")]
     use values::specified::url::SpecifiedUrl;
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
@@ -20,6 +20,7 @@
         use std::fmt;
         use style_traits::cursor::Cursor;
         use style_traits::ToCss;
+        #[cfg(feature = "gecko")]
         use values::specified::url::SpecifiedUrl;
 
         #[derive(Clone, PartialEq, Copy, Debug)]
diff --git a/components/style/properties/longhand/position.mako.rs b/components/style/properties/longhand/position.mako.rs
index a556481dc2b..da7fe080604 100644
--- a/components/style/properties/longhand/position.mako.rs
+++ b/components/style/properties/longhand/position.mako.rs
@@ -178,8 +178,10 @@ ${helpers.predefined_type("flex-basis",
 
                 use std::fmt;
                 use style_traits::ToCss;
-                use values::HasViewportPercentage;
-                use values::specified::{AllowQuirks, ${MinMax}Length};
+                % if not logical:
+                    use values::specified::AllowQuirks;
+                % endif
+                use values::specified::${MinMax}Length;
 
                 pub mod computed_value {
                     pub type T = ::values::computed::${MinMax}Length;
@@ -219,7 +221,9 @@ ${helpers.predefined_type("flex-basis",
                     type ComputedValue = computed_value::T;
                     #[inline]
                     fn to_computed_value(&self, context: &Context) -> computed_value::T {
-                        use values::computed::${MinMax}Length;
+                        % if not logical or "block" in size:
+                            use values::computed::${MinMax}Length;
+                        % endif
                         let computed = self.0.to_computed_value(context);
 
                         // filter out keyword values in the block direction
@@ -332,7 +336,6 @@ ${helpers.predefined_type("object-position",
         animation_value_type="none">
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
     use values::computed::ComputedValueAsSpecified;
 
     pub type SpecifiedValue = computed_value::T;
@@ -424,8 +427,6 @@ ${helpers.predefined_type("object-position",
     use std::ops::Range;
     use str::HTML_SPACE_CHARACTERS;
     use style_traits::ToCss;
-    use style_traits::values::Css;
-    use values::HasViewportPercentage;
     use values::computed::ComputedValueAsSpecified;
 
     pub mod computed_value {
diff --git a/components/style/properties/longhand/svg.mako.rs b/components/style/properties/longhand/svg.mako.rs
index bd1a2b520a1..9d531ca58a1 100644
--- a/components/style/properties/longhand/svg.mako.rs
+++ b/components/style/properties/longhand/svg.mako.rs
@@ -77,7 +77,6 @@ ${helpers.single_keyword("mask-mode",
     pub use properties::longhands::background_repeat::single_value::SpecifiedValue;
     pub use properties::longhands::background_repeat::single_value::computed_value;
     pub use properties::longhands::background_repeat::single_value::RepeatKeyword;
-    use properties::longhands::background_repeat::single_value;
 
     #[inline]
     pub fn get_initial_value() -> computed_value::T {
diff --git a/components/style/properties/longhand/table.mako.rs b/components/style/properties/longhand/table.mako.rs
index 3b1c8709a94..b64deb64606 100644
--- a/components/style/properties/longhand/table.mako.rs
+++ b/components/style/properties/longhand/table.mako.rs
@@ -14,7 +14,6 @@ ${helpers.single_keyword("table-layout", "auto fixed",
                    spec="Internal-only (for `<col span>` pres attr)"
                    animation_value_type="none"
                    internal="True">
-    use values::HasViewportPercentage;
     use values::computed::ComputedValueAsSpecified;
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
diff --git a/components/style/properties/longhand/text.mako.rs b/components/style/properties/longhand/text.mako.rs
index 4d29e2b0e77..7d0aa234e09 100644
--- a/components/style/properties/longhand/text.mako.rs
+++ b/components/style/properties/longhand/text.mako.rs
@@ -16,7 +16,6 @@
                    spec="https://drafts.csswg.org/css-ui/#propdef-text-overflow">
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
     use values::computed::ComputedValueAsSpecified;
     use cssparser;
 
@@ -107,7 +106,6 @@ ${helpers.single_keyword("unicode-bidi",
                    spec="https://drafts.csswg.org/css-text-decor/#propdef-text-decoration-line">
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
     use values::computed::ComputedValueAsSpecified;
 
     impl ComputedValueAsSpecified for SpecifiedValue {}
@@ -237,7 +235,6 @@ ${helpers.predefined_type(
                    spec="https://drafts.csswg.org/css-inline/#sizing-drop-initials">
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
     use values::computed::ComputedValueAsSpecified;
     use values::specified::{Number, Integer};
 
diff --git a/components/style/properties/longhand/ui.mako.rs b/components/style/properties/longhand/ui.mako.rs
index 05808307635..25cba0609c5 100644
--- a/components/style/properties/longhand/ui.mako.rs
+++ b/components/style/properties/longhand/ui.mako.rs
@@ -35,10 +35,8 @@ ${helpers.single_keyword("-moz-window-dragging", "default drag no-drag", product
                    products="gecko"
                    animation_value_type="none"
                    spec="None (Nonstandard Firefox-only property)">
-    use cssparser::Token;
     use std::fmt;
     use style_traits::ToCss;
-    use values::HasViewportPercentage;
     use values::computed::ComputedValueAsSpecified;
 
     no_viewport_percentage!(SpecifiedValue);
diff --git a/tests/unit/style/attr.rs b/tests/unit/style/attr.rs
index 25fe085a637..6bf72a5b969 100644
--- a/tests/unit/style/attr.rs
+++ b/tests/unit/style/attr.rs
@@ -5,7 +5,6 @@
 use app_units::Au;
 use style::attr::{AttrValue, LengthOrPercentageOrAuto, parse_length};
 use style::values::computed::CalcLengthOrPercentage;
-use style_traits::values::specified::AllowedLengthType;
 
 #[test]
 fn test_length_calc() {
diff --git a/tests/unit/style/restyle_hints.rs b/tests/unit/style/restyle_hints.rs
index b2e2cf3e999..c50cfcc87bb 100644
--- a/tests/unit/style/restyle_hints.rs
+++ b/tests/unit/style/restyle_hints.rs
@@ -6,7 +6,7 @@
 fn smoke_restyle_hints() {
     use cssparser::Parser;
     use selectors::parser::SelectorList;
-    use style::restyle_hints::{DependencySet, RESTYLE_LATER_SIBLINGS};
+    use style::restyle_hints::DependencySet;
     use style::selector_parser::SelectorParser;
     use style::stylesheets::{Origin, Namespaces};
     let namespaces = Namespaces::default();
diff --git a/tests/unit/style/stylist.rs b/tests/unit/style/stylist.rs
index 3c136edcef3..42fc3a8f6a0 100644
--- a/tests/unit/style/stylist.rs
+++ b/tests/unit/style/stylist.rs
@@ -212,7 +212,7 @@ fn test_insert() {
 #[test]
 fn test_get_universal_rules() {
     thread_state::initialize(thread_state::LAYOUT);
-    let (map, shared_lock) = get_mock_map(&["*|*", "#foo > *|*", "*|* > *|*", ".klass", "#id"]);
+    let (map, _shared_lock) = get_mock_map(&["*|*", "#foo > *|*", "*|* > *|*", ".klass", "#id"]);
 
     let decls = map.get_universal_rules(CascadeLevel::UserNormal);